The cheetah's deep, resonant purr always captivates visitors to a South African wildlife centre devoted to the world's fastest mammal. But some South Africans are less enthusiastic about the animals, which can beat a Ferrari in a 60-yard sprint. The De Wildt Trust says the rise of private game farming has intensified a long conflict between farmers and the endangered carnivore that has seen at least 200 wild cheetahs — from a wild population that may now be as low as 250 — killed or removed from their wild habitat in South Africa over the last two years.